Racetrack memory or domain-wall (DW) memory is currently being researched as an alternative to solid-state memory devices. The potential advantage to this new technology is higher storage density higher than flash memory and much higher read/write performance than hard disks. However there are a number of problems that must be overcome in order to make the technology commercially feasible.
An example of a current impediment to DW memory is explained in: M. Kläui et al., Phys. Rev. Lett. 95, 026601 (2005). In summary direct application of current in the data element (to translate the domain walls) may cause heating, deform the DWs and/or cause information loss.